Screw power press



June 23, 1931. w ZEH 1,810,996

SCREW POWER PRESS Filed July 27, 1929 2 Sheets-Sheet l Y; INVEN X? I M ATTORNEY'S June 23, 1,931.. 5. w. ZEH

SCREW POWER PRESS Filed July 27. 1929 2 Sheets-Sheet 2 mvemgz BY ATTORNEY s.

Patented June 23, 1931 UNITE STAT S PATENT 'o-FFICE EDMUND w. ZEH, or NEWARK, NEW-JERSEY scnEw POWER PRESS Application filed July 27,

, This invention relates in general to that class of power presses in which a head for carrying one die is moved toward and away from a bed supporting a fixed die by a screw which is alternately rotated in opposite directions by alternate engagement of a pair of friction discs with opposite sides of a friction wheel carried by the screw, the invention being more particularly directed to the drivspeed toward "its periphery at increasing.

2 'speed. This is quite desirable. ,On the re- "turn stroke the friction wheel starts at'the periphery of the drive disc athighg-speed and travels at gradually decreasing speed.

This is objectionable because, dueto the'massz and inertia of thefriction wheel and the fact that the coefficient of friction is low at high speed, considerable loss of power and wear and tear on the friction surfacesare sustained, while efiiciency of the press is. lowered by 80 slow pick-up and return of the friction wheel and the head operated thereby to starting position. This is true especially of large presses, wheresomet-imes the friction drive disc fails to raise the friction wheel.

One object of my invention is to provide novel and improved means for overcoming the foregoing objections and atithe same time retaining all of the advantages in presses of the character described.

7 Another object is to provide a power press of this character whereinsaid friction drive "discs are so constructed and arrangedthat the friction .wheel is driven on the down stroke of the screw as usual with gradually increasing speed,' while onthe upstroke said friction wheel is started at slow speed Where the 'coefficient of friction is high so that the friction wheel is moved on the return stroke without difiiculty. L3 Other objects areto provide such apower 1929. Serial no. 381,658.

press 'wherein the return-stroke drive disc is; rotated .atlower speed than the ,down

stroke disc; toprovidea power [press of the general character described in which the return-stroke drive disc is composed of two sections rotating at' different speeds, with the section of lower speed to contact with the frlct on wheelfor initiating the return stroke; to provide a return stroke drive disc comprising" a circular body section concentric w th the drive shaft and an annular concentric r m section with the faces of said sectlons 1n acommon plane; to provide means for rotating said sections at different speeds;

and to obtain other advantages and results as willbe morefully brought out by the following description. V ;Referring to the accompanying drawings, 1n which like numerals: of reference indicate the same parts throughout the several views,

Figure 1 is a front elevation of a power press embodying my invention.showing, the

friction drive discs in transverse'section.

'Figure 2 1s a similar 'viewofa modified form of the invention, the power shaft being omitted; and I 7 Figure 3is a like view the invention. H Y Y Specifically describing the embodiment of the invention illustrated by Figures 1 to 3,

of another form of inclusive, the numerall designates the frame" of the press which is provided with an elongated vertically disposed opening 3 extend- 1ng transversely through the frame at its longitudinal center, said openings being formed at the lower end thereof with a bed 4 adaptedto receive a fixed'die (not shown).

The; sides of the opening 3 are provided with vertlcal guides '5 upon and between which is mountedavertically slidable head 7-adapted to carry another die (not shown) to oooperate with thefiXed die."- This head 7 is carried by the lower end of a vertical screw 8 which has ,a suitable swivel connection withthe head and extends upwardly through thetop of the frame 1, the upper end there- "of being provided with a horizontally disposed wheel 'Qhavingafriction surface 10 I "on its"periphery.' Itis obvious, therefore,

Struction bel'observedfthat the frie yond one bearing, as indicated at 16. Mount-" ed on the shaft 11 at diametrically opposite points on the edge of the friction wheel 9 is a pair of friction drive members such as discs 18 and 19, adapted to alternately engage thelfriction surface 10 of the wheel 9 to rotate the screw 8. i r

Any suitable means ."may be utilized for driving-the discs 18 and 19, but as shown I may provide a pulleyfsurfacei 20 on the outer'side of each disc and connect said pulley surfaces to'the respective driving pulleys 21 and 22, on apower shaft. 23 to which power may be applied by abeltand pulley 24L from any suitablesource. Assuming the shaft 11 to be rotating in the direction of the arrows onFigures 11'1and'2, it willbe obvious that asthe friction disc "19 engages the wheel9, thejhead 7 will be forced upwardly, while engagement of the disc 18withthe wheel 9 will move the head 7 downwardly. To acomplish the alternate enga 'e'ment of the friction discs 18and 19 with the friction wheel 9the shaft 11 is slidable in its bearings. For the purpose I of longitudina lly sliding the shaft 11 any'suit'able mechanism may beutili'zed, forfe2iample," the mechanism described in my Patent No.- 1,32l,095, dated December 9, 1919 or I may use a fluid pressure device comprising a cylinder 25 secured to the frame of the pressrand within which is t reciprocable a piston 26 connected to the shaft 11. Fluid pressure may be alternately supplied to and vented from opposite sides 'of'the piston 26 through pipes 27 by anysuitablevalvledevice (not shown), e In accordance withthe. invention the two discs 18 and 19 are to be rotated at different speeds," the disc 19- for driving :the'friction wheel 9 on the up-stroke ofthe screw 8being rotated at a lower speed than, the disc 18 for actuating the screw 8on the down-stroke Forthis purpose, the down-stroke drive disc 18- may be keyed or otherwiserigidly secu'red'to the shaft 11 as at '28, while the disc 19 is rotaiable relatively tothe shaft-L, The respectiveidriving pullevs'21 and 22 are of such relative'sizes to the corresponding discs 18 and 1921s 1 to drive the disc 18 at a higher speed than the disc'19; :Both discs 18. and 19 are held against longitudinal movement on the shaft by theoollars 29," With-this con.-

,atvwhichvthe coeflicient of the friction is much hi her than at the speed of thedisc 18 and riction wheel 9 at the end of the clown-stroke. Loss of power and wear and tear on friction surfaces of the disc 19 and friction wheel are thus avoided and the friction wheel is raised without difliculty at-a gradually decreasing speed.

In the form of the inventionshown in Fig ure 2 the connection of the friction drive disc 18 to the shaft 11 and its connection to the drive pulley 21 are identical to that shown in Figure 1 of the drawings. The other drive disc 30 is of different construction and comprisesacentral body portion or section 31 keyed at 32 upon theshaft 11 and surrounded by a coaxial annular rim section 33 which is rotatable upon the hub portion 3 1 of the central section 31. The rim section 33 has con nected therewith a pulley surface 330 which is y pulley 22' as connected by a belt to the drive is the drive disc 19 of Figure 1. p f With this construction it will be observed that the central section 31 of the drive disc 30 is rotated at the same speed as the drive of the drive disc 30 is rotated at a lower speed. Therefore, the, friction wheel 9 and .100 disc 18,while the annular rim section 33' screw 8 are actuated on their down-stroke with gradually increasing speed, as in the construction shown in Figure 1. The initial movement of the friction wheel on the return stroke effected by theyannular rim 33 rotating "at a lower speed. As the friction wheel rises it. passes from the rim section 33 into contact with the outer portion of .the central section 31 where the speed of the wheel'is increased and then gradually decreased as the point of contact of the friction wheel with the central section 31 approaches the center of the latter. .It will be observed that the friction surfaces of the two sections 31 and33 are in thesameplane transversely to the axis of the shaft. 11', and only enough clearance is provided between-the edge of the central section and the inner periphery of the rimvsection to permit relative rotation of the sections.

The shaft 11 may be longitudinally moved to causealternate engagement of the discs 18 and 30 with'the friction wheel9, by the same means described in connection 'with Figure 1. V

In Figure 3 of the drawings is shown an other form of the invention is genis keyed fied and changed eral identical with-that shown in Figure 2 .the only difference .being in the manner of driving the rim section 35 of thedrive disc 36. Inthis form of the invention, the rim section 35 is provided with a hub 37 to which a gear 38 which meshes with a pinion 39 j ournaled on a stud shaft 40 onthe arm 15 of the press frame. The pinion 39 is rigidly connected to a pinion 41 which in turn meshes with a gear 42 keyed to the hub 43 of the central section 44.-

With this construction it will be observed that power from the shaft 11 will be transmitted through the gear 42, pinions 41 and 39 to the gear 38 so as to rotate the rim section 35. The ratio of the gearing is such as to rotate the rim section 35 at a lower speed than the central section 44, just as the rim section 33 is rotated at a lower speed than the central section 31 in the construction shown in Figure 2 of the drawings. The operation of this form of the invention is otherwise identical with that shown in Figure 2.

While I have shown and described the in vention as embodied in certain details of construction, it should be understood that this 1s primarily for the purpose of illustrating the principles of the invention and that the details of construction may be widely modiby those skilled in the art without departing from the spirit or scope of the invention.

Having thus described my invention, what I claim is:

1. In a power press, the combination with a frame, a screw mounted in said frame, a head on one end of said screw and a friction wheel on the other end, of coaxial friction drive members at opposite points on the edge of said friction wheel, means for rotating said drive members at difierent speeds, and means for causing alternate engagement of said friction drive members with said friction wheel.

2. Ina power press, the combination with a frame, a screw mounted in said frame, a head on one end of said screw and a friction wheel on the other end, of coaxial friction drive members at opposite points on the edge of said friction wheel, a shaft rotatably movable in said frame for supporting said members, one of said members being rigidly secured upon said shaft and the other member being rotatable relatively to said shaft, means for rotating said shaft to drive one of said drive members, means for rotating the second-mentioned friction drive member at a different speed, and means for causing alternate engagement of said friction drive members with said friction wheel.

3. In a power press, the combination with a frame, a screw mounted in said frame, a head on one end of said screw and a friction wheel on the other end, of a shaft in said frame parallel to the plane of said friction wheel.

said friction wheel, means for wheel and longitudinally movably mounted in said at a diflerent speed, dinally moving said'shaft for for causing alternate engagement, of said frictional rive members with saidv friction 4. In a power press, the combination with a frame, ascrewmounted 1n said frame, a head on one end of S316; scr

wheel on'theiother end, of a shaft rotatable and longitudinally movably mounted in said frame parallel to the planev of said friction wheel, friction drive members mounted on said shaft against movement longitudinally:

of the shaft at opposite points. on the edge of rotating said friction drive members at different speeds, and means for longitudinally'moving said shaft for causing alternate engagement of said friction drive members withsaid friction wheel.

5. In a power press, the combination with a frame, a screw mounted in said frame, a head on one end of said screw and a friction on the other end, of a shaft rotatable frame parallelto the plane of said friction wheel, friction drive *membersmounted on said shaft against movement longitudinally of the shaft at opposite points on the edge of said friction wheel, saidfriction drive members being respectively rotatable withand relatively to said; shaft, means for rotating said shaft todrive one of said drivemembers, means for rotating the other drive member and means l for longitucausing alternate engagement of said frictionzdrive members with said friction wheel. I

In a power press, the combination with a frame, a screw mounted in said frame, a

ew and a friction 7 head on one end of said screw and a friction wheel on the other end, ofa pair of friction drive members at opposite points on the edge of said friction wheel, one of said members comprising a central body section and an. annular concentric rim section, means for rotating said sections of the first-mentioned drive member, at different speeds, means for rotating the other drive member -and means for causing alternate engagement of said drive members with saidIfriction wheel.

7. n a power press, the combination with a frame, a screw mounted in said frame, a

head on one end of said screw and a friction wheel on the other end, of apair of friction drive membersat opposite points on the edge of'said friction. wheel, one of said members comprising a central bodysection and an annular concentric rim section, means for rotating theotherdrive member, means for rotating the central body section of the first-mentioned drive member at the same speed, means for. rotating the rim section of of the first-mentioned rigidly mounted on said shaft and the rim '35 section of said first-mentioned drive member the first mentioned member at another speed,

and means for causing alternate engagement of said drive members with said friction wheel.

8. In apowerpress, the combination with a frame, a screw mounted in said frame, a head on one end of said screw and a friction wheel on the other end, of a pair of friction drive'members. at opposite points on the edge of said friction wheel, one of said 'members comprising a centralbody section and an annular concentric-rim section, a shaft rotatable in said frame, the other drive member and the central section of the firstmentioned drive member being rigidly mounted on said shaft and the rim section of said first-mentioned drive member being rotatable relatively to said shaft, means for rotating said shaft, means for rotating the rim section of the first-mentioned drive member at a different speed, and means for causing alternate engagement of said drive mem bers with said friction wheel.

9. Ina power press, the combination with a frame, a screw mounted in said frame, a head on one end of said friction drive members at opposite points on theedge of said friction wheel, one of said members comprising a central body section and an annular concentric rim section, a shaft longitudinally movable and rotatable in said frame, the otherdrive member and the central section drive -member being being rotatable relatively to and held against longitudinal movement on said shaft, means for rotating said shaft, means the rim section of the first-mentioned drive member at a different speed, and means for longitudinally moving said shaft to cause alternate engagement of saidv drive members with said friction Wheel; r

l 10. In a power press, the combination with a frame, a screw mounted in head'on one end of saidscrew and a friction wheel on the other end,of =a-pair of friction drive discs rotatable" at opposite points on the edge of saidfriction wheel, one of said discs comprising arcentral body section and a relatively 'rotatably coaxial annular .:rim section having/their friction surfaces in a common plane transverseto their axis, means for rotating said actions of the first-mentioned drive disc at different speeds, means for rotating the other drive disc, and means for causing alternate engagement of said drive discs with said friction wheel.

11. In a powerpress,the combination with a frame, a screw mounted in said frame, a tion drive members at opposite points on the tion wheel on the other end, of coaxial friction drive members at opposite points on the edge of said frictionwheel'to drive said-friction wheel on its working stroke and its return-stroke respectively, means for rotating said drivemembers in the same direction and the return stroke drive member at arlower speed than the other drive member, and

means for causing alternate engagement of said friction drive members with said friction wheel. a I I i W: ZEH.

for. rotating i l. Ml 

